1. Field of the Invention
The present invention relates to a method and an apparatus for manufacturing an optical element such as a lens, a prism, a mirror, etc.
2. Description of the Related Art
As a conventional method for manufacturing an optical element by heating and shaping an optical element material (heat softening material), a method has been employed as one of many widely accepted methods, in which a material or a material integrated with a retainer is heated so that the material is softened to a desirable level, the material is moved onto a press shaft (onto the shaping mold center shaft) so that the material is pressed.
In order to shape an optical element at a high accuracy, the temperatures of heated materials have to be kept consistent even when they are located in different places. However, it is very difficult to convey materials from a heating position to a desired position to shape them while keeping their temperature consistent.
Meanwhile, a method for manufacturing an optical element has been proposed in which a material is heated while it is floated in gas, is softened sufficiently, and thereafter is dropped onto a shaping mold so that the material is pressed (Japanese Laid-open Patent Publication No. 08-133758, for example).